A monolithically integrated laser may be a laser that is fabricated on a single wafer, such as an Indium Phosphide (InP) wafer. A tunable laser may be a laser with an output wavelength that may be continuously altered in a controlled manner across a significant wavelength range. A tunable laser may be controlled by injecting current or heat into a tuning apparatus. Such heat and/or current may cause the tuning apparatus to selectively change, which may result in a concentrated optical output of the desired wavelength. Many structures may be employed to control optical output in the monolithically integrated laser and/or in other optical transmission contexts.